/Engine/Source/Runtime/ClothingSystemRuntimeCommon/Public/ClothPhysicalMeshData.h
Compute vertex normals as unweighted average of incident face normals. If all incident triangles are degenerate, the vertex normal is assigned a value of FVector3f::XAxisVector.
void ComputeFaceAveragedVertexNormals ( [TArray](API\Runtime\Core\Containers\TArray)< FVector3f > & OutNormals ) const